Multiple fuse plug



Dec. 27, 1949 W. C. LINTON MULTIPLE FUSE PLUG Filed May 27, 1948 Patented Dec. 27, 1949 2 UNITED STATES PATENT OFFICE 2,492,301 MULTIPLE FUSE PLUG William C. Linton,.Washington, D. C.

1948, Serial No. 29,571

2 Claims. (Cl. 200-121) Application May 2'1,

The present invention relates to fuse units of the multiple plug fuse type and the primary object of the invention is to provide a suitable enclosure for multiple plug fuses which shall be sufficiently tight to prevent lint and dust collecting around the fusible links therein and becoming ignited when a fusible link is blown and yet each fusible link will be in place for performing successively when short-circuits occur.

Other objects will be in part obvious and in part pointed out hereinafter.

In the accompanying drawings:

Fig. 1 is a side elevation of the fuse unit embodying the invention.

Fig. 2 is a vertical transverse sectional view.

Fig. 3 is a vertical transverse sectional view taken substantially at right angles to that of Fig. 2.

Fig. 4 is a horizontal sectional view taken on the line 4-4 of Fig. 2 in the direction of the arrow points.

Fig. 5 is a plan view of the cover plate.

Fig. 6 is a fragmentary enlarged plan view of the casing. f

Fig. 7 is a perspective view of .one of the fuse links.

Fig. 8 is a Fig. 9 is a section of the latter taken on the line 9-9 of Fig. 8 in the direction of the arrow points.

This multiple plug-type fuse unit comprises a casing l preferably formed from porcelain having external threads for receiving a conventional screw contact shell 2. A flat headed contact rivet 4 extends through the casing l and is provided with a split extremity 3.

The casing I is provided with a centrally located chamber 5 and an opening 6 through which extends rivet 4. Radially extending from and communicating with the chamber 5 are a plurality of vertically extending compartments 1, preferably eight in number, and each capable of receiving a fusible link 8. Each compartment 1 is of sufiicient area, as best shown in Fig. 4 of the drawings, as to permit any molten metal given off by the rupture of the weakened portion of the fuse link therein to remain or settle therein and the separating walls between each compartment prevent the spattering of this molten metal into an adjacent compartment as would render the fuse link therein inoperative. The upper end of the casing l is enlarged to provide an annular flange 9. Formed within the upper face of this casing is an annular groove or chanplan view of the floating contact, and

- l are the vertically extending nel-way l0 establishing a fiat surface ll upon which rests the brass contact ring l2 and a flat annular surface 13 which latter separates the fuse link compartments 1 from the channel-way l0. Shallow recesses M are also formed in the upper face of the casing to establish the flat sur face l5 over each of which extends the upper bent over section iii of a fusible link 8. Also formed diametrically opposite within the casing slots 11 through each of which extend a leg I8 bent downwardly from the brass contact ring l2 and the outer extremities of these legs l8 are connected to the screw contact shell 2 by means of the solder connections l9.

A cover plate preferably moulded from Bakelite extends over the upper end of the cas ing I and has an outer flange 2| which latter is capable of riding within the annular groove 22 of the casing and is provided with a centrally located boss extending within the chamber 5. A washer 23 is placed upon the central portion of the cover plate 20 and the split ends 3 of the contact rivet extend thereover for retaining the cover plate upon the casing and yet permit the free rotation thereof. This plate 20 is also provided with a depending annular flange 24 projecting within the channel-way 10 of the casing.

A housing 25 is formed with the cover plate 20 having a compartment therein in which freely floats a contact plate 26. This contact plate is stamped from one piece of brass having one arm 21 capable of riding upon the contact ring 12 and its opposite arm 28 adapted to contact with each upper end 16 of the fusible links. A coil spring 29 is also provided for normally retaining the arms 21 and 28 and fusible links.

A depending leg 30 is also formed with the contact plate 26 and extends within the annular channel-way H! of the casing so that when contacting the cam-shaped lugs 3| this contact plate 26 will be moved upwardly out of contact with the ring I2 and fusible links.

A pair of spaced lugs 32 are formed with the upper face of the cover plate and have a snapwith the lamp housing 33. Arranged within the lamp housing is a neon indicating lamp 34 and leak resistor 35. One lead wire 36 of the lamp extends beneath the washer so as to have a connectionwith the contact rivet 2 whereas another lead wire 31 connects the lamp and resistor 35 in series with the coil spring 29.

Formed within the upper face of the housing 25 in contact with the ring is a recess 38 and extending diametrically therewith said casing and extending within said through is a vertical wall or partition 41 for dividchannel-way thereof, a cover plate rotatably ing the recess into two separate compartments. mounted upon said casing, a flange carried by said the lead wire 31. This lead wire 31 extends of the ends of said fuse links arranged adjacent through .a slot 44 as it enters the recess 38. From 1 said channel-way within the said casing and a this it is apparent that the coil spring 29 is sepdepending leg formed with said contact plate arated from the lead wire 31 and by placing whereby upon the rotationof's'aid cover plate said within the recess 38 any suitable resistance comdepending leg will be caiised to ride upon said position or that disclosed in my former Patent No. cam shaped pro ectioh for moving said contact 2,206,780, dated July 2, 1940, a leak resisting conplate out of contact with said contact ring and nection 35 will be established therebetween. one of the ends of said fuse links against the Within the chamber 5 and about the fusible action of said contact retaining means links within the compartments 1 is placed an are 2. .A multiple enclosed plug fuse comprising in rotating within the casing I. the upper face thereof between said explosion By grasping the lamp housing 33 and turning chamber and said flange, lugs formed with said the same in a clock-wise direction the contact casing and positioned equidistance apart within the curved forward end of the leg 39 rides one of shell contact, a contact ring mounted upon said the lugs 3| whereupon the contact plate 26 will be 30 flange and connected toscrew shell contact, fuse moved upwardly and out-of contact with the ring link arran ed Wi hin the explosive chamber of 12 and a fusible link. Upon further rotation the i casing h h v neend onnect d to said leg 30 will pass over the lug 3i and a ain drop rivet Contact, a rotatable v r p a a nwithin the channel-way 10 so as to effect a snap tact member carried by said cover plate, means contact with the ring 12 and the next succeeding wher by upon the rotation of said cover plate fusible link Each lug 31 is piovided with an insaid lugs W111 cause said contact member to be clined sur face so that the curved forward end of moved Into and t Of o tact With said contact the 'leg 30 may ride thereupon but the outer exring and the free ends of Sald se kS. a flange tremity of the leg 30 will prevent the cover plate formed h id Ver plate and depend from turning in an anti-clockwise direction by 40 Within d a y contacting the straight wall of a lugSl opposite WILLIAM C. LINTON. to that where the inclined sui face is formed.

As the lamp is connected in series with the con- REFERENCES CITED tact terminals 2 and t in pa with the The following references are of record in the fusible links it .glow only when a fusible link w of this I ciaim: UNITED STATES PATENTS 1. A multiple fuse plug comprising in combina- Number Name .Date tion a casing, .a rivet contact centrally located 1,855,086 Bladholm Apr. 19, 1932 within said casing, a screw shell contact sui- 1,939,663 Cole Dec. 19, 1933 rounding said casing and spaced from said rivet 1,957,137 F'erry et al.. May '1, 1934 contact, a contact ring mounted Within said 1,959,250 Pfeiifer May 15, 1934 casing and connected to said screw shell contact, 1,974,694 starck Sept, 25, 1934 fuse links each having one end connected to said 2,058,264 Schiller Oct. 20, 1936 rivet contact, said casing having an annular 2,075,516 Freeman Mar,.30, 1.937 channel-way formed therein and arranged be- 2,206,785 Linton .July 2, 1940 tween said contact ring and the opposite ends of 2,284,599 .Altschule May 26, 1942 saidfuse links, cam shaped projections formed 2,287,010 Altschule June 23, 1942 plate 26 will be caused to move therewith until the channel-way thereof, a contact rivet, ascrew 

